Chronic lymphocytic leukemia (CLL/SLL) and mantle cell lymphoma (MCL) should be excluded in these cases; helpful markers include LEF1 (normally positive in B-CLL/SLL) and TCL1 (SMZL is mostly negative, in contrast to CLL/SLL and MCL, both of which are normally TCL1-positive) [7] while staining for SOX11 might be of limited values, splenic MCL is often negative [8]. This evidence concerns the gene SOX11 and B-cell chronic lymphocytic leukemia.